1. Field of the Invention
The present invention concerns an improved transducer or, in other words, an element for reproducing and/or recording sound, in particular a loudspeaker or microphone.
For clarity's sake, the following description will only deal with transducers for reproducing sound, in other words sound reproducers.
In particular, the invention concerns piezo-electric reproducers of the type which make use of a vibration membrane onto which is fixed a piezo-ceramic disc.
This membrane is usually fixed to a holder in the shape of a frame or the like, along its perimeter, whereby it is glued to this holder along its perimeter with a hard or flexible glue.
2. Discussion of the Related Art
It is known that by applying an alternating voltage to the piezo-ceramic disc, the material of the piezo-ceramic disc will start to expand or shrink, and, as the membrane itself cannot expand or shrink, the whole will bend as a function of the voltage variations, as a result of which a sound signal will be generated which is proportional to the frequency and the amplitude of the applied signal.
In Belgian patents 1,011,085 and 1,011,559 of the applicant are described improvements to the aforesaid type of transducers whereby use is made of a metal membrane and whereby, in the case of patent BE 1,011,559, an elastic muffling layer made of silicones is provided on this metal membrane, comprising metal particles such as lead or the like.
A disadvantage of such a transducer with a muffling layer with metal particles is that these metal particles are very hard to recover from the muffling layer, so that these particles cannot be recycled and, as a consequence, when the transducer is discarded, it will end up on the waste heap and thus form a burdening for the environment.
In Belgian patent number 1,013,592 of the applicant, additional improvements to the aforesaid type of transducers are described whereby, in this case, a membrane is applied made of a material muffling sound vibrations, in particular a soft material such a plastic or the like.
Although the reproducers, as described in the aforesaid patents, offer very good results, the invention aims an improved transducer with unequalled results in the field of sound quality, which moreover is less harmful to the environment when being discarded.